Road reinforcement sheet, structure of asphalt reinforced pavement and method for paving road

ABSTRACT

A paved road including a reinforcement sheet layer ( 1 A) and a pavement layer ( 22 ), in which the reinforcement sheet layer ( 1 A) includes an asphalt layer ( 2 ) laminated to at least one side of a reinforcement sheet ( 1 ) including a composite material that is impregnated with a thermoplastic resin to achieve a volume content of a continuous glass fiber, which is a reinforcement fiber, of not less than 30% and not moere than 85% is proved.

TECHNICAL FIELD

The present invention relates to a road reinforcement sheet in asphaltpaved roads that can significantly improve durability to cracking andrutting due to traffic, and to an asphalt reinforced paved road usingthe road reinforcement sheet concerned, and especially to a roadreinforcement sheet effective in reinforcing and making thinner asphaltpaved road, and to an asphalt reinforced paved road. Furthermore, thepresent invention relates to a method for paving that enables thin layerpavement of a road, and to a method for repairing a paved road.

BACKGROUND OF THE INVENTION

In recent years, damages on road pavement occurs and safety andcomfortableness of traveling are lowered due to the increased amount ofroad traffic and of large-sized car traffic. Especially in road pavementof heavy traffic route line, many damages as rutting by flowing ofasphalt, cracking, etc. are observed. In order to secure traffic safety,remedial work is performed frequently and, as a result, social problemis being caused. Moreover, if cracking occurs on road pavement,rainwater will permeate therefrom and it will result in hurting subbasecourse further and promoting cracking. In bridge deck pavement, waterthat permeates into reinforced concrete floor slab from on bridge deckthrough asphalt pavement not only makes steel rod and steel materialsinside the floor slab corroded, but especially promotes degradation ofconcrete, and of the floor slab concrete under conditions of repeatedload applied, and then load-carrying capacity and durability areadversely affected.

Various methods are proposed in order to improve these rutting and crackof road pavement. As a general method, a cutting overlay method in whichasphalt effective in rutting that has high anti-flowability and highabrasion resistance, and asphalt effective in crack prevention that hashigh crack-proof property are used for asphalt pavement as an asphaltmixture maybe mentioned. However, at present, these methods offerneither effective solution for suppressing both of rutting and crack ofasphalt pavement face nor large life extension of the paved road.

Moreover, various methods and compositions that reinforce overlay ofasphalt pavement are proposed. For example, as shown in Japanese PatentLaid-Open No. 62-268413 or Japanese Patent Laid-Open No. 64-14415, thereis so-called geotextile method. In geotextile method, geotextiles areapplied on subgrade, subsequently granular material, such as bankingmaterials or gravel, are applied thereon, and pavement subbase course isformed to disperse and support load applied on the pavement. However, inthis method of construction, most effects over damage on rutting, crack,etc. that take place on asphalt pavement surface are not demonstrated.

Moreover, a method is proposed in which a shearing force inside asphaltmixture in asphalt pavement is restrained to reinforce asphalt mixtureusing geotextile. As examples aiming at improvement in reinforcementperformance of asphalt mixture, for example, an example in which a gridcomprising uniaxially/biaxially drawn material of synthetic resin isused, and an example in which a grid comprising strands with glass fiberimpregnated with resins is used may be mentioned.

However, a drawn portion of the grid of this synthetic resin has quite alow tensile strength of 0.4 GPa, and then in order to reinforce asphaltmixture, quite a big basis weight is needed. Moreover, also in a gridusing glass fiber, a defect is observed in which tensile strength fallsby cutting of fiber by being worn and hooked at the time of pavingasphalt.

Moreover, in these grids of glass fiber, or synthetic resin grid havinghigh rigidity, in order to obtain high material strength, rigidity as ageotextile is set high. These geotextiles cannot be continuously rolledout at the time of application, and for this reason, difficulty inhandling when applied is observed.

Besides, since this geotextile is used being inserted between lowerlayer and upper layer of asphalt, slide prevention and bonding strengthbetween the upper layer and the lower layer need to be strengthened.Therefore, this geotextile has a form of grid. Consequently, it has adefect that decay of subbase course and subgrade by rainwater coming invia cracks that take place on asphalt pavement surface or damage portioncannot be prevented.

As a result of wholehearted research by the present inventors in orderto solve the above described problem, it turned out that asphaltpavement is strengthened and permeation of rainwater etc. is effectivelyprevented by using a sheet for road reinforcement given in JapanesePatent Laid-Open No. 09-177014, and a big effect is demonstrated therebyto reflection crack and crack of asphalt surface course.

In the above described Japanese Patent, a sheet for road reinforcementhas compatibility with asphalt pavement, at a temperature of asphaltmixture at the time of application (usually not less than 110° C.),asphalt of the sheet for road reinforcement melts, and forms a goodplane for joint between asphalt pavement and the sheet, and unites withit. By this adhesive effect demonstrated, the sheet for roadreinforcement can suppress a flow of asphalt pavement, and also candecrease a deflection of pavement material, resulting in suppression ofphenomenon of rutting or crack. Consequently, it is indicated that thedurability of not less than double is demonstrated compared with usualpaved roads to phenomenon of crack or rutting observed on a roadsurface.

Besides, as shown in Japanese Patent Application No. 07-083678, a sheetfor road reinforcement of this Japanese Patent Laid-open No. 09-177014also has waterproofing function as a compound waterproofing sheet, andhas reflection crack preventive ability, and also has waterproof abilityfor bridge deck pavement.

However, damage of asphalt pavement has become markedly increased due toincrease in automobile traffic and enlargement of truck in recent years.Moreover, since requests to paved road from user of road or residentsalong the route is diversified, a pavement with special function inwhich outstanding durability, safety of traffic, environment, and costreduction and long life are taken into consideration is desired, andtherefore various multifunctional pavements are developed. As examples,drainage pavement with drainage function and noise reduction function,thin layer asphalt pavement, recycled improved asphalt mixture usingrecycled aggregates, and heated asphalt mixture in which slag of moltenand cooled incinerated ashes of domestic wastes, crushed waste glass,waste plastic, piece of cutting of waste PET bottle, etc. are mixed asaggregate attract attention recently.

For example, a drainage pavement technical guiding principle (proposal)about drainage pavement is published, and in it asphalt with highviscosity is usually used as a binder of asphalt mixture used for adrainage pavement, and emulsified rubberized asphalt as tack coat.

Even if a sheet for road reinforcement given in Japanese PatentLaid-Open No. 09-177014 is used to an asphalt pavement using theseasphalt mixtures, sufficient effect may not be demonstrated to crack andrutting that are formed in an asphalt pavement face.

The present inventors proceeded further a research about materials andmethods for manufacturing, etc. that also support such variousmultifunctional pavements and that can also solve these problems.

The present invention is to offer a paved road that may cancel the abovedescribed defects.

One of the further large subjects of the present invention is decreasingan amount of asphalt used for pavement, i.e., enabling thin surfacing(thin layer pavement) with thickness of asphalt made thinner.

Thickness of asphalt used for pavement of road is indicated by variousoutlines and references. For example, according to MANUAL FOR ASPHALTPAVEMENT (1975 fiscal year version, 6–19 pages: Japan Road Association),thickness of surface asphalt is designed based on traffic of car;

-   A-case (less than 250 cars/day): Surface course asphalt 5 cm,-   B-case (ibid. 250–1000 cars/day): Surface course asphalt 5 cm,-   C-case (ibid. 1000–3000 cars/day): Surface course asphalt 10 cm,-   D-case (not less than 3000 cars/day): Surface course asphalt 15    cm*. * Included binder course

Besides, according to asphalt pavement basic lecture; design of pavementof asphalt (Nichireki Kagaku Kogyo), it indicates that “generally,asphalt mixture is finished one layer up to 6 cm of thickness, andbeyond it, finished in multilayered on the basis of 5 cm in thickness”,and also that “(as thickness of asphalt) surface course with a thicknessof 5 cm on an upper subbage course may be made - - - omitting bindercourse, on the basis of 10 cm of standard for sum total of surfacecourse and binder course, in the case where unit section automobiletraffic is less than 2000 sets/day.”

Besides, although Japanese Patent Laid-Open No. 9-177014 is a patentusing a reinforcement sheet and there is indicated that a strength of aroad improves by use of a reinforcement sheet, but only an examinationresult of a road with a thickness of 5 cm is indicated in Example.

It was considered that it was very difficult to make a thickness of asurface course asphalt thinner than 5 cm from the above described designvalue etc. As described above, in road pavement, actual situation wasthat a subject was not taken into consideration in which a thickness isto be made thinner, based on old customs or regulations of constructionoutline etc. that surface course asphalt is to be not less than 5 cm.

It requires time of construction that thick asphalt is used, and hugequantity of asphalt is used for it.

Furthermore, in repair of a road, or reconstruction of asphalt, cuttingof the asphalt is needed, and cutting generates noise and dust,therefore a great trouble is made to residents along the route, andlegal restrictions are also applied about noise.

If asphalt used is thick, a long construction period will be required,and increase in an amount of cutting asphalt abandonment andconstruction period over a long period of time lead to problems in whichinfluences on financial or environmental problems, such as trafficinterception over a long period of time, bad environment for residentsalong the route, and high road repairing expense etc. become larger. Itis very serious subject to mitigate these problems.

DISCLOSURE OF THE INVENTION

The present invention solves the above described problems and aims atproviding a road reinforcement sheet that may markedly decrease damagesof rutting and crack, etc. generated on asphalt pavement surface, and anasphalt reinforced paved road using the road reinforcement sheetconcerned, and especially at providing a road reinforcement sheeteffective in reinforcing and thin-layering of asphalt paved road, andthe asphalt reinforced paved road.

The present inventors have come to complete the present invention, as aresult of repeated and wholehearted examination in order to attain theabove described purpose. That is, the present invention includes thefollowing invention.

(A) A paved road including reinforcement sheet layer (1A) and pavementlayer (22), in which

said reinforcement sheet layer (1A) includes an asphalt layer (2)laminated to at least one side of a reinforcement sheet (1) includingcomposite material that is impregnated with thermoplastic resin so thata volume content of a continuous glass fiber is not less than 30% andnot more than 85% using the continuous glass fiber as reinforcementfiber.

(B) The paved road according to (A) in which the reinforcement sheetlayer (1A) is further a reinforcement sheet layer (1B) having a wovenfabric layer or a nonwoven fabric layer (3) containing natural fiber orsynthetic fiber on at least a part of face between the reinforcementsheet (1) and the asphalt layer (2).

(C) The paved road according to (A) including reinforcement sheet layer(1A) and pavement layer (22) in which

said reinforcement sheet layer (1A) includes an asphalt layer (2)laminated to both sides of a reinforcement sheet (1) including acomposite material that is impregnated with a thermoplastic resin sothat a volume content of a continuous glass fiber is not less than 30%and not more than 85% using the continuous glass fiber as reinforcementfiber.

(D) The paved road according to any of (A) to (C), in which

the reinforcement sheet (1) has

a tensile strength of not less than 290 MPas,

a tensile elongation of not more than 10%,

a coefficient of thermal expansion of 2×10⁻⁶ to 8×10⁻⁶/°C., and

a thickness of 100 micrometers to 600 micrometers.

(E) The paved road according to any of (A) to (D), in which the asphaltlayer (2) has a thickness of not less than 400 micrometers and not morethan 2000 micrometers.

(F) The paved road according to any of (A) to (E), in which

when shearing peel strength being performed for the reinforcement sheet(1) and the asphalt layer (2), the layers are bonded mutually bystrength of not less than force of coagulation of asphalt layer (2).

(G) The paved road according to any of (A) to (F) comprising

a notably thin pavement layer having a pavement layer (22) with athickness of less than 50 mm whose fracture energy by bending test isnot less than 4 [kN-mm], and

a function notably excellent in crack-proof performance.

(H) The paved road according to any of (A) to (G) comprising

a notably thin pavement layer having a pavement layer (22) with athickness of less than 50 mm whose dynamic stability by wheel trackingtest is not less than 600 [turn/mm], and

a function notably excellent in rutting-proof property.

(I) The paved road according to any of (A) to (H) in which

the pavement layer (22) has drainage property, and the reinforcementsheet layer (1A or 1B) has seepage control property, comprising

a function of draining rainwater in a direction of road shoulder alongupper surface of the reinforcement sheet layer (1A or 1B) withoutpermeating rainwater penetrated via the pavement layer (22) into subbasecourse.

(J) The paved road according to any of (A) to (I) in which

thickness of the pavement layer (22) is not more than 4.5 cm.

(K) The paved road according to (J) in which

thickness of the pavement layer (22) is 4 to 1.5 cm.

(L) A structure of a road in which

the reinforcement sheet layer (1A or 1B) according to any of (A) to (C)is applied and the road reinforcement sheet makes a surface coursewithout asphalt applied thereon.

(M) A structure of temporary road used during road repairing in which

the reinforcement sheet layer (1A or 1B) according to any of (A) to (C)is applied and the road reinforcement sheet makes a surface coursewithout asphalt applied thereon.

(N) A repairing method of a paved road in which

in case of formation of crack, rut, or loss portion on a pavementsurface on the paved road with asphalt or concrete, the structure of thepaved road according to any of (A) to (K) is prepared after at least apart of a surface of the paved road is cut, and after the crack or theloss portion is partially repaired if needed.

(O) A repairing method of a paved road in which

the structure of the paved road having a function of draining rainwaterin a direction of road shoulder according to (I) is prepared after asurface is cut and a crack or loss portion is partially repaired on thepaved road with asphalt or concrete.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing one embodiment of a paved roadaccording to the present invention;

FIG. 2 is a perspective view showing another embodiment of a paved roadaccording to the present invention;

FIG. 3 is a figure showing a cross section of a road reinforcement sheetlayer used in FIG. 1;

FIG. 4 is a figure showing a cross section of a road reinforcement sheetlayer used in FIG. 2;

FIG. 5 is a figure showing an outline of one embodiment of equipmentmanufacturing a road reinforcement sheet of the present invention;

FIG. 6 is a figure showing an outline of other embodiment of anequipment manufacturing a road reinforcement sheet of the presentinvention;

FIG. 7 is a sectional view of a general pavement constitution accordingto the present invention;

FIG. 8 is a sectional view of a general pavement constitution used foran application examination of a road reinforcement sheet of the presentinvention;

FIG. 9 is a pavement constitution sectional view of an applicationexamination in which a road reinforcement sheet of the present inventionis paved on a subbase course and subsequently a binder course and asurface course are paved;

FIG. 10 is a pavement constitution sectional view of an applicationexamination in which a binder course is paved on a subbase course, aroad reinforcement sheet of the present invention is paved, andsubsequently a surface course is paved;

FIG. 11 is a pavement constitution sectional view of an applicationexamination in which a road reinforcement sheet of the present inventionis paved on an existing RC floor slab after cutting of existing roadsurface, and subsequently a binder course and a surface course arepaved;

FIG. 12 is a pavement constitution sectional view of an applicationexamination in which a road reinforcement sheet of the present inventionis paved on an existing lower layer mastic asphalt layer after cuttingof existing road surface, and subsequently a binder course and a surfacecourse are paved;

FIG. 13 is a pavement constitution sectional view of an applicationexamination in which a road reinforcement sheet of the present inventionis paved on a cut road surface after cutting of existing road surface,and subsequently a binder course and a surface course are paved;

FIG. 14 is a pavement constitution sectional view of an applicationexamination in which a road reinforcement sheet of the present inventionis paved by floor slab thickening method on a road surface after jetcement application, and subsequently a surface course is paved;

FIG. 15 is a conceptual view of a bending test measuring method; and

FIG. 16 is a conceptual view of a wheel tracking test measuring method.

EXPLANATION OF LETTERS OR NUMERALS

1A: Road reinforcement sheet, 1B: Road reinforcement sheet, 1:Reinforcement sheet, 2: Asphalt layer, 3: Woven fabric or nonwovenfabric comprising fibers, 4: Surface course (asphalt mixture), 5: Bindercourse (asphalt mixture), 6: Subbase course, 7: Lower layer subbasecourse (crusher-run), 8: Upper subbase course (mechanically stabilizedcrushed stone), 9: Styrene foam board, 10: Layer of asphaltstabilization, 11: RC floor slab, 12: Mastic asphalt layer, 13: Cuttingroad surface, 14: Jet cement, 15: Drainage pavement, 16: Molten adheredlayer, 17: Heater, 18: Heating roll, 19: Cooling roll, 20: Vat, 21: Rollfor application, 22: Solid tire, 23: Load, 24: Imitation subbase course

PREFERRED EMBODIMENTS OF THE INVENTION

The present invention relates to a road reinforcement sheet in which onboth sides of a reinforcement sheet (1) having a tensile strength of notless than 290 MPas, a tensile elongation of not more than 10%, acoefficient of thermal expansion of 2×10⁻⁶ to 8×10⁻⁶/°C., and athickness of 100 micrometers to 600 micrometers an asphalt layer (2)having a thickness of not less than 400 micrometers and not more than2000 micrometers is bonded to the reinforcement sheet (1) with not lessthan a force of coagulation of the asphalt layer (2) in shearing peelstrength, and to a structure of an asphalt reinforced paved road inwhich crack performance and rutting-proof performance are markedlyimproved in which the road reinforcement sheet concerned is paved at adepth of less than 5 cm from an asphalt surface side of an asphaltpavement to be reinforced.

A paved road of the present invention is notably excellent incrack-proof property, and has fracture energy by bending test of notless than 4 [kN-mm], and in general 4 to 40 [kN-mm]. Moreover, it isexcellent also in wheel tracking property, and has a dynamic stabilityof not less than 600 turn/mm, and in general about 600 to 15000 turns.

The present invention provides a structure of an asphalt reinforcedpaved road with markedly improved crack performance and rutting-proofperformance in which a road reinforcement sheet is paved at a depth ofless than 5 cm, preferably less than 4.5 cm, and more preferably 4 to1.5 cm from an asphalt surface side of the asphalt pavement to bereinforced. Moreover, the present invention also includes a temporaryconstruction road used during road repairing in which a roadreinforcement sheet is paved, and the road reinforcement sheet makes asurface course without paving asphalt thereon.

A road reinforcement sheet of the present invention and a structure ofan asphalt reinforced paved road using the road reinforcement sheetconcerned will be hereinafter described in detail using drawings.

A reinforcement sheet (1) of the present invention is a sheet-likesubstance that has a tensile strength of not less than 290 MPas, atensile elongation of not more than 10%, a coefficient of thermalexpansion of 2×10⁻⁶ to 8×10⁻⁶/°C., and a thickness of 100 micrometer to600 micrometers, and is not especially limited as long as it has theabove described performances. For example, although metal foil andcomposite material etc. may be mentioned, it is preferable to choose areinforcement sheet (1) that may bond so that a shearing peel strengthbetween the reinforcement sheet (1) and an asphalt layer (2) of thepresent invention may be more than a force of coagulation of the asphaltlayer (2). In the light of such viewpoints, it is preferable to usecomposite materials comprising reinforcement fibers and polymer resinsas reinforcement sheets (1).

Although the kind of fiber is not especially limited when usingcomposite materials as a reinforcement sheet (1) of the presentinvention, for example, glass fibers, carbon fibers, aramid fibers,silicon carbide fibers, etc. are typical examples. As especiallypreferable fiber, glass fibers may be mentioned, and more preferablycontinuous glass fibers.

Moreover, as thermoplastic resins used for reinforcement sheet (1) ofthe present invention, although they are not especially limited, forexample, polypropylenes; polyethylenes; ethylene propylene copolymers;polyolefins based resins, such as homopolymers and copolymer ofα-olefins; homopolymers, such as styrene and methyl styrene; polystyrenebased resins, such as copolymers of these monomers and α-olefins;homopolymers of vinyl chloride; polyvinyl chloride based resins, such ascopolymers of the monomer and α-olefins may be used. In addition,various kinds of resins, such as AS resins, ABS resins, ASA resins(polyacrylonitrile-polystyrene-polyacrylate), polymethylmethacrylates,nylons, polyacetals, polycarbonates, polyethylene terephthalates,polyphenylene oxides, fluororesins, polyphenylene sulfides,polysulfones, polyether sulfones, polyether ketones, polyether etherketones, polyimides, and polyarylates, may also be used, and in thelight of strength, abrasion resistance, price, and reproductive easinessas waste, as most desirable resins, general-purpose polyolefin basedresins, such as polyethylenes and polypropylenes, and polystyrene basedresins, polyvinyl chloride based resins, and nylons are recommended.

When composite materials are used as reinforcement sheets (1) of thepresent invention, it is preferable to make thermoplastic resinsimpregnated so that a volume content of the reinforcement fiber may bein a range of not less than 30% and not more than 85%, and morepreferably of not less than 30% and not more than 80%.

When a strength of the sheet and flexibility are taken intoconsideration, a thickness of the reinforcement sheet (1) of the presentinvention is preferably 100 micrometers to 600 micrometers, and morepreferably 150 micrometers to 550 micrometers. A sufficient strength maybe obtained with thickness of reinforcement sheet (1) of not less than100 micrometers, flexibility of the sheet is suitable with thickness ofless than 600 micron, and good application property as a roadreinforcement sheet may be demonstrated.

Various methods may be mentioned in order that a reinforcement sheet (1)of the present invention may attain both performances of not less than10% of degree of tensile elongation, and 2×10⁻⁶ to 8×10⁻⁶/°C. ofcoefficient of thermal expansion, and in the case where a compositematerial is used as a reinforcement sheet (1), it is preferable to use areinforcement sheet (1) in which a plurality of sheets whereincontinuous reinforcement fibers are arranged in one direction andimpregnated in a thermoplastic resin are orthogonally laminated.

As long as a method for manufacturing a sheet impregnated inthermoplastic resin used in a method of the present inventiondemonstrates the above described physical properties, it will not beespecially limited, and for example, the sheet may be manufactured by amethod given in Claims and Examples of Japanese Patent Publication No.4-42168.

In claim 1 of the Publication, a method is disclosed in which while athermoplastic resin is applied to at least one belt of a pair of beltsheated not less than softening point of the thermoplastic resin theapplied film is introduced between a pair of belts that face each other,and the thermoplastic resin is impregnated into fibers by passing afiber sheet between the one pair of belts to manufacture a fiberreinforcement sheet-like prepreg, and methods being dependent to themethod in detail are indicated. More specifically, it is constituted byfiber delivery section, feeding section, resin impregnating section, andtaking up section as shown in this Publication FIG. 1, and details ofFIG. 1 are indicated in detailed description.

A prepreg used in the present invention is indicated in Japanese PatentLaid-Open No. 9-177014.

In a prepreg of the present invention, reinforcement fiber has aconstitution in which continuous filaments are aligned almost uniformlyin one direction. As fibers used for a prepreg, although, for exampleglass fibers, carbon fibers, aramid fibers, silicon carbide fibers, etc.are typical examples, they are not limited to them. As especiallypreferable fibers, glass fiber may be mentioned.

As the fibers, fibers are usually used in which predetermined number ofyarns or rovings that have 200 to 12000 monofilaments with thickness of3 to 25 micrometers in strand are arranged in one direction. When glassfiber is used as the fiber, various kinds of surface treatments areusually applied to increase adhesion with resins. Surface treatment isapplied combining binders and coupling agents.

As a specific example of manufacturing method of a prepreg, a methodcurrently indicated by Japanese Patent Publication No. 04-042168, forexample, may be mentioned. In the case of glass fiber, by this method,for example, surface of a monofilament with a thickness of 13 micron istreated with γ-methacryloxy-propyl trimethoxy silane, and 1800 of themare bundled to obtain a yarn without twist. While aligned in onedirection 80 yarns are pulled by uniform tension, resin is applied tothe yarns, subsequently pressed by heating roll, and made to impregnateinto the yarns to manufacture the prepreg.

Further, more specifically, a method for manufacturing a prepreg isindicated in paragraph (0032) of Japanese Patent Laid-Open No. 9-177014,and a method for manufacturing a reinforcement sheet is indicated inparagraph (0034), and what are manufactured by this method may be used.Preferably, a reinforcement fiber is glass fiber and a resin ispolypropylene. For example, “Preglon” (Trade name: manufactured byMitsui Chemicals, Inc.) may be used.

Moreover, in a reinforcement sheet (1) of the present invention, wovenfabric layer or nonwoven fabric layer (3) comprising fiber materials maybe configured on whole surface or a part of one side or both sides. Inthis case, as woven fabric or nonwoven fabric used for reinforcementsheet (1), a cloth generally comprising fibers, such as natural fibers,for example, hemp and cotton as vegetable fibers; silk and wool asanimal fibers; asbestos as mineral fiber; and a cloth made from polymerfibers and polymer filaments; for example, high molecular weight highdensity polyethylenes, polypropylenes, polyvinyl chlorides,polyvinylidence chlorides, polystyrenes, polyvinyl alcohols, polyesters,and nylons; and various copolymers of them may be used. Although wovenfabric or nonwoven fabric comprising polyesters and various copolymersof them, etc. are preferable when processing temperature in producingreinforcement sheet (1) and processing temperature at time of subsequentpreparing asphalt layer (2), etc. are taken into consideration, there isnot especially any limitation.

An amount of basis weight per unit area of a woven fabric or nonwovenfabric comprising fiber materials used in the present invention is 10g/m² to 500 g/m^(2,) and preferably is 15 g/m² to 60 g/m^(2.) Usingwoven fabric or nonwoven fabric comprising such fiber materials, asphaltis impregnated into fiber material portion to increase adhesive strengthand also durability of a road reinforcement sheet itself.

A road reinforcement sheet of the present invention may be obtained bycarrying out heat welding of an asphalt layer (2) at both sides of theabove described reinforcement sheet (1).

As materials that constitute asphalt layer (2) used in the presentinvention, straight asphalt, blown asphalt, improved asphalt, etc. maybe mainly mentioned, and more preferably improved asphalt may bementioned. As long as asphalt layer (2) used for the present inventionsatisfies this condition, there is not any other limitation.

There may be obtained improved asphalt with modifiers, such as rubbersand thermoplastic elastomers, added thereto raise 60° C. viscosity,besides semi-blown asphalt with raised viscosity that is obtained byoxidation polymerization caused by air blown into a straight asphalt athigh temperature, as this improved asphalt, and all of these improvedasphalts may be used for the present invention. Rubbers, resins, etc.are used as modifiers for improved asphalt. Rubbers used as additivesare usually synthetic rubbers, and styrene butadiene rubbers,styrene-butadiene block copolymers, styrene butadiene copolymers,chloroprene butadiene nitrile copolymers, isobutylene isoprenecopolymers, etc. may be mentioned. Generally the amount of addition ofthe rubbers is 2 to 5 weight %. Moreover, in addition, styrene-isopreneblock polymers and ethylene-vinylacetate copolmers (EVA),ehtylene-ethylacrylate copolymer (EEA) etc. may be mentioned.

In a road reinforcement sheet of the present invention, 60° C. viscosityof an asphalt layer (2) of the road reinforcement sheet of the presentinvention is raised, and anti flowability, adhesive property withadherend, and toughness are improved using improved asphalt as theasphalt layer (2). Consequently, the adhesive property between thereinforcement sheet (1) and the asphalt layer (2) will improve further.Moreover, as mentioned above, performance of the asphalt layer (2) isimproved and, as a result, the road reinforcement sheet concerned firmlyadheres to asphalt pavement and substrate adherend, etc., mechanicalperformance of the reinforcement sheet (1) maybe given to asphaltstructure, and thereby rutting and crack generated in asphalt pavedroads may be efficiently suppressed.

Thickness of an asphalt layer (2) of the present invention is usually300 micrometers to 4000 micrometers, and preferably 400 micrometers to2000 micrometers. An amount of asphalt of an asphalt layer (2) issuitable in thickness of the asphalt layer (2) being not less than 300micrometers, and while formation of a layer is possible, adhesion withsubstrate layer at the time of application is excellent. Moreover, whena thickness of an asphalt layer (2) is not more than 4000 micrometers,there are no problems at time of manufacturing a road reinforcementsheet such as degassing, thickness irregularity, and surface property,and the road reinforcement sheet is flexible, weight is suitable andapplication property at the time of application is well demonstratedwhile layer formation of the asphalt layer (2) is attained.

As a method for manufacturing a road reinforcement sheet of the presentinvention, a method is adopted in which a reinforcement sheet (1) isheated at more than melting temperature of a thermoplastic resin usedfor the reinforcement sheet (1), then the reinforcement sheet (1) and anasphalt layer (2) concerned are melted or admixed, and subsequentlysolidified and uniformly laminated.

Also in the case where a woven fabric or nonwoven fabric (3) comprisingfiber materials is configured on whole surface or a part of one side orboth sides as a reinforcement sheet (1) a thermoplastic resin andasphalt are melted or admixed mutually, and subsequently solidified anduniformly laminated in a portion of fiber materials. In this case, in aninterface of the thermoplastic resin and the asphalt, a state is formedin which the thermoplastic resin and asphalt are melted or admixedmutually to fiber materials and solidified, and a constitution of a kindof composite material is formed. Consequently, adhesive strength betweenthe reinforcement sheet (1) and the asphalt layer (2) improves, and thedurability of the road reinforcement sheet itself also further improves.

Generally as a method for manufacturing a road reinforcement sheet,although there are a method in which the reinforcement sheet (1) isdipped into molten asphalt in the state where it is heated or not heatedat not less than the melting temperature of a thermoplastic resin usedfor the reinforcement sheet (1) concerned, and a method of roll coatingmay be mentioned, there is no limitation for the method formanufacturing as long as a sheet is obtained in which asphalt layer (2)is melted or admixed mutually to both sides of the target reinforcementsheet (1) to form a solidified state.

A road reinforcement sheet of the present invention has a reinforcementsheet (1) having a tensile strength of not less than 290 MPas, a tensileelongation of not more than 10%, a coefficient of thermal expansion of2×10⁻⁶ to 8×10⁻⁶/° C., and a thickness of 100 micrometer to 600micrometers, as component. As an example, when a reinforcement sheet (1)in which a plurality of sheets wherein continuous reinforcement fibersare arranged in one direction and impregnated in a thermoplastic resinare orthogonally laminated is used, a tensile strength of the roadreinforcement sheet concerned shows a strength of not less than 49 kNsper meter, and a tensile elongation shows not more than 10%.

Moreover, since the road reinforcement sheet concerned has the asphaltlayer (2) with thickness of 400 micrometers to 2000 micrometers as theuppermost surface course, adhesive property with adherend as componentof pavement, such as asphalt paving mixture and concrete floor slab, isvery highly demonstrated. Moreover, since asphalt layer (2) is bondedwith not less than cohesion of asphalt layer (2) in shearing peelstrength with reinforcement sheet (1) in a road reinforcement sheet ofthe present invention, it becomes possible that a state maybe formedwhere asphalt paving mixture and concrete floor slab, etc. as adherendand the reinforcement sheet (1) concerned are firmly bonded by combiningwith asphalt paving mixture used for asphalt paving. Therefore, itbecomes possible to give mechanical performance of the reinforcementsheet (1) to asphalt structure to improve strength of the asphaltpaving, and while crack formed on the asphalt paving is reduced, ruttingby flow of asphalt paving mixture is inhibited.

Moreover, since asphalt layer (2) is bonded with not less than cohesionof asphalt layer (2) in shearing peel strength with reinforcement sheet(1) in a road reinforcement sheet of the present invention, it is firmlybonded with asphalt paving mixture, concrete floor slab, etc. asadherend. Thereby, since mechanical performance of the reinforcementsheet (1) may be efficiently demonstrated, traffic is possibleespecially as a temporary road, without carrying out paving of anasphalt mixture on the road reinforcement sheet concerned after pavingof the road reinforcement sheet concerned.

In the present invention, when a reinforcement sheet in which aplurality of sheets wherein continuous reinforcement fibers are arrangedin one direction and impregnated in a thermoplastic resin areorthogonally laminated is used as a reinforcement sheet (1), this effectmay be still highly demonstrated.

Next, a structure of an asphalt reinforced paved road using a roadreinforcement sheet of the present invention will be described. Althougha structure of usual asphalt paving is constituted on a subgrade insequence of a subbase course, a binder course (5), and a surface course(4), in some case a surface course (4) may be paved directly on asubbase course (6) without a binder course (5). Moreover, whenfoundation is a soft ground, sometimes asphalt stabilization method inwhich asphalt (straight asphalt, emulsified asphalt, cutback asphalt,etc.) is added into local material or materials with supplementarymaterial added thereto on a subgrade and is processed may be performed.A subgrade represents a portion with a thickness of 1 m under pavement,and is a portion 1 m under from a face of finished banking in banking,and a portion 1 m under from a face in excavated face in cut portion. Asubgrade serves as foundation that determines a thickness of thepavement.

A subbase course is a layer made to disperse traffic load and safelytransmit to a subgrade. Therefore, it must be a layer in which materialshaving sufficient bearing capacity and is moreover rich in durabilityfastened and hardened enough with required thickness. In order to obtainan economically and dynamically balanced configuration, a subbase courseis usually paved being divided into a lower layer subbase course (7)with cheaper materials having comparatively small bearing capacitytherein, and an upper subbase course (8) with better-quality materialshaving bigger bearing capacity. Materials used for the lower layersubbase course (7) and the upper subbase course (8) are local materials,mechanically stabilized crushed stone, crusher-run slag, pit gravel, pitrun gravel, or sand.

A surface course (4) and a binder course (5) are portions mostinfluenced by traffic load or atmospheric phenomena action, and hotasphalt mixture is used here. As kind of hot asphalt mixture, a coarsegrade asphalt concrete in binder course (5), a dense grade asphaltconcrete, a fine grade asphalt concrete, and dense grade gap asphaltconcrete in surface course (4) are used as a standard. In recent years,asphalt mixture for drainage pavement may be used sometimes forreduction of noise, and rainwater elimination on road surface. Inselection of asphalt paving mixture used for a surface course (4) and abinder course (5) of the present invention, selection is done inconsideration of atmospheric phenomena conditions, traffic conditions,application conditions, etc., and there is not especially limitation.

As a structure of an asphalt reinforced paved road of the presentinvention, a structure in which a road reinforcement sheet is paved on acutting road surface (13) or a subbase course (6), and a binder course(5) and a surface course (4) are paved in sequence, or only a surfacecourse (4) is paved, and a structure in which a road reinforcement sheetis paved on a binder course (5) and a surface course (4) is then pavedmay be mentioned. Such structures are selected based on constitutions ofa road, application of a road reinforcement sheet (for example, in orderto suppress crack of asphalt paving face, to suppress rutting by flow ofasphalt, to reinforce asphalt mixture for drainage pavement, toreinforce thin surfacing, to pave water resistant layer under asphaltpaving etc.) and application conditions.

As a method of forming a structure of an asphalt reinforced paved roadof the present invention, a method in which attaching is carried out onan adherend to which the road reinforcement sheet is paved while pouringheated and molten asphalt, a method in which attaching is carried out onan adherend by melting asphalt on front face of road reinforcement sheetwith torch burner, and a method in which attaching is carried out on anadherend with heat of asphalt mixture used for asphalt paving may bementioned, and the method is not especially limited as long as adhesionis carried out to the adherend with enough strength.

Although examples will be shown below as methods for forming a structureof an asphalt reinforced paved road of the present invention, thepresent invention is not limited with following examples.

When a crack of an asphalt paving face is suppressed using a roadreinforcement sheet, heated and molten asphalt is poured on cutting roadsurface (13) to cover the crack of the road surface, and the roadreinforcement sheet concerned is applied, while leveling concavo-convexof the road surface.

After the completion of paving of a road reinforcement sheet, in thecase where a surface course (4) is laid and spread, a temperature of anasphalt paving mixture needs to be surely not less than 110° C. In thecase of not more than 110° C., application must not be carried out.After surface course (4) is laid and spread, iron ring roller andpneumatic tire roller are used for compaction, and thereby heat isconducted to a binder course (5) to melt the asphalt, and as a resultthe binder course (5), the road reinforcement sheet, and the surfacecourse (4) are unified further firmly.

When carrying out a pavement with remarkably excellent ruttingperformance using a road reinforcement sheet, the road reinforcementsheet concerned is applied on binder course (5). In this case, as abinder course (5), for example, a coarse grade asphalt blend is laid andspread by an asphalt finisher etc. on a subbase course (6), pressed andcompacted using iron ring roller and pneumatic tire roller forcompaction, and subsequently road reinforcement sheet is paved. As amethod of paving the road reinforcement sheet concerned and of adheringto adherend, a method in which the road reinforcement sheet concerned ispaved while heated and molten asphalt is poured on a road surface, or amethod in which the road reinforcement sheet is directly paved, and thesheet is melted with heat of the binder course (5) to be adhered to thebinder course (5) if a temperature of the binder course (5) afterpressed and compacted is not less than 110° C. may be mentioned.However, when a temperature of the binder course (5) after pressed andcompacted is not more than 110° C., the road reinforcement sheet isdirectly heated with a direct fire of torch burners etc. to melt thesheet, and the road reinforcement sheet is paved while being adheredwith the binder course (5). After completion of paving of the roadreinforcement sheet, in the case where a surface course (4) is laid andspread, a temperature of an asphalt paving mixture needs to be surelynot less than 110° C. In the case of not more than 110° C. applicationmust not carried out. After surface course (4) is laid and spread, ironring roller and pneumatic tire roller are used for compaction, andthereby heat is conducted to a binder course (5) to melt the asphalt,and as a result the binder course (5), the road reinforcement sheet, andthe surface course (4) are further firmly unified.

In order to greatly raise performance to suppress crack formed on asurface of a paved road and rutting by flow of asphalt that are primaryobjects of the present invention it is necessary that location may beadjusted where road reinforcement sheet is paved, and thickness ofasphalt mixture layer on the road reinforcement sheet concerned may beadjusted. That is, in order to raise greatly crack suppressionperformance formed on the surface of paved road, it is preferable topave the road reinforcement sheet in a portion near forming source ofthe crack. Moreover, in order to greatly raise suppression performanceof rutting by flow of asphalt, it is preferable to pave the roadreinforcement sheet concerned in a portion near asphalt front face ofthe surface course (4), and it is still more preferable to pave the roadreinforcement sheet concerned in a portion of asphalt front face in lessthan 4 cm from the surface course (4).

Generally in maintenance and repairing of asphalt paved road of thesedays, a method is adopted in which asphalt mixture is poured intodamaged part as a temporary measure for repairing rutting and crackformed on asphalt paving front face. However, this repairing method isnot an essential repair but a temporary solution method, and damagesmaybe formed in the asphalt paving face again by passage of time.Therefore, in general, evaluation is to be carried out to these asphaltpaved roads, and construction using replacing method and cutting overlaymethod, etc. are adopted.

However, when a replacing construction method is carried out, thereoccur problems such as, long construction period, generation of noise,construction expense, a large amount of scrap materials and their greatprocessing expense, and a large amount of materials (expense) used forreplacing (for example, asphalt mixture) etc.

And, also when a cutting overlay method is adopted, there occur problemssuch as, long construction period, construction expense, a large amountof scrap materials (cut materials) and necessity for great amount oftheir processing expense, and amount (expense) of asphalt mixture foroverlaying.

When these problems are taken into consideration, it will becomeeffective solution for construction period, construction expense, etc.to form an asphalt reinforced paved road using a road reinforcementsheet of the present invention. That is, the following advantages arementioned when forming an asphalt reinforced paved road using a roadreinforcement sheet of the present invention.

A road reinforcement sheet of the present invention is firmly bondedwith an asphalt paving mixture used for an asphalt paving road and aconcrete floor slab, etc. and thereby it becomes possible to givemechanical performance of the reinforcement sheet (1) to asphaltstructure to improve strength of the asphalt paving, and while crackformed on the asphalt paving is reduced, rutting by flow of asphaltpaving mixture is inhibited. Therefore, it becomes possible to reduce anamount and a thickness of asphalt paved on the road reinforcement sheetof the present invention. Accordingly, a thickness in cutting damagedasphalt paving front face may be mitigated only into a surface coursepart of the damage part, and this will lead to reduction of amount ofscrap materials (cut materials), to reduction of expense, and toshortening of construction period.

A road reinforcement sheet of the present invention, and a structure ofan asphalt reinforced paved road using the road reinforcement sheetconcerned has outstanding performance that shows a durability in ruttingand crack of asphalt paving formed on a road front face of not less thanthree times and not less than 1.5 times respectively compared with usualroad, and therefore they are a road reinforcement sheet and a structureof asphalt reinforced paved road useful in economical efficiency,environment property, etc. in case of maintenance repair work of asphaltpaving.

Although the present invention is hereinafter described still in detailby drawings and Examples, the present invention is not limited to thefollowing Examples.

Various kinds of test methods used in the specification are conductedaccording to “Pavement Examination Method Manual” (the 14th issue of“Japanese Road Association” Nov. 16, 1998 first edition). Mainexamination methods are shown below.

Bending Test

In bending test, measurement was conducted under conditions of −10° C.and loading rate 50 mm/min as shown in FIG. 15, using a 50 mm×50 mm×300mm piece of a sample comprising a reinforcement sheet layer and anasphalt layer (dense-graded 13 mm-straight asphalt: 60/80 parts). Arrowshows a load.

Fracture Energy of Bending Test

Area under a curve to a peak load in load-deformation curve in the abovedescribed bending test was defined as a fracture energy.

In obtaining a peak load, “Bending destruction quality and tensilesoftening curve of steel fiber reinforcement concrete” (“Japan Societyof Civil Engineers memoir: 1993 No. 2, 460V-18, page 57”) was used as areference. Measurement of an area under a curve to peak load in aload-deformation curve was based on references below.

-   (1) “Characteristics of Glass Fiber Reinforcement cement”:-   Composite material technical collection II-6-6, glass fiber    reinforcement cement (GRC),-   (2) “Characteristics of glass fiber reinforced concretes (GRC)”:    Japan Society for Composite Materials magazine volume 13, No.    2 (1987) page 58.

Wheel Tracking Examination (Dynamic Stability)

Measurement was conducted as shown in FIG. 16, using a 300 mm×300 mm×50mm piece of a sample comprising a reinforcement sheet layer-a bindercourse (dense-graded 13 mm-straight asphalt: 60/80 parts)-an asphaltmixture (straight asphalt, improved asphalt, drainage property asphalt,etc.) under conditions of 60° C., load 70 kgf, and load velocity 42pass/min. Measurement was carried out at 50 mm from surface course or 30mm from surface course (binder course 20 mm). Arrow shows a movementdirection of a load.

EXAMPLE

Experiment 1 manufacture of a road reinforcement sheet

[Manufacture of a road reinforcement sheet]

A road reinforcement sheet in which asphalt layers (2) were laminated onboth sides of a reinforcement sheet (1) was manufactured with equipmentshown in FIG. 5. The reinforcement sheet (1), while being heated at notless than 180° C. with infrared heater from both sides, was passedthrough a container filled with asphalt heated at 200° C. at a rate of 5m/min, thus asphalt was applied, passed between heating rolls heated at180° C., subsequently passed between cooling rolls heated at 60° C. forcooling while thickness was adjusted. Thus, a road reinforcement sheetwas obtained. As a reinforcement sheet (1), “Preglon” manufactured byMitsui Chemicals, Inc. was used.

In this sheet, polyester nonwoven fabric with 15 g/cm² was arranged onboth sides using a method of Example 1 of Japanese Patent Laid-Open No.9-177014 using a sheet comprising glass fiber and polypropylene. A sheetwas used that was additionally squeezed through with rolls within acontainer filled with asphalt in order to have it further mixed in aninterface of the reinforcement sheet (1) and an improved asphalt layer(2), and in order to improve asphalt impregnation into nonwoven fabric.

(Improved asphalt used in this Example has properties of softening pointof 110° C., penetration 20 to 30, viscosity (180° C.) of 6 Pa·s, andspecific gravity of 1.02.)

“Preglon” which content of glass fiber is 50 wt. %, having a thicknessof 270 micrometers, has physical properties of a tensile strength of 395MPa, a tensile elongation of 2.2%, and a coefficient of thermalexpansion of 5×10⁻⁶/°C.

Experiment 2 basic physical properties of a road reinforcement sheet

Basic physical properties of the road reinforcement sheet obtained bythe above described experiment are shown below (Table 1), and they werecompared with similar sheets for the tensile strength (Table 2). Assimilar sheets, sheets of 2 mm thickness and 3 mm thickness were used inwhich nonwoven fabric was used for core material, and asphalt wasimpregnated. Tensile test was conducted according to JIS K7113 “Tensiletest method of plastic.” As for shearing adhesive strength andperpendicular adhesive strength, measurement was carried out accordingto “Floor slab waterproofing quality standard test method” by JapanHighway Public Corporation.

A tensile strength of the road reinforcement sheet showed a strength ofnot less than five times as high as conventional sheet materials.

TABLE 1 Basic physical properties of the road reinforcement sheet ItemsMeasured value Tensile strength (length/width) 68.6 kN/m Shearingadhesive strength 328 N/cm Perpendicular adhesive strength 66.6 N/cm²

TABLE 2 Tensile strength comparison of the road reinforcement sheet andsimilar sheets Test piece Tensile strength (kN/m) Road reinforcementsheet 68.6 Similar sheet 1 for comparison (2 mm 12 thickness) Similarsheet 2 for comparison (3 mm 8 thickness)

Experiment 3 performance comparison for crack suppression effectiveness

In a case where a road reinforcement sheet obtained in experiment 1 wasused, where a sheet was not used, and where a similar sheet was used,“bending test” and “repeated bending fatigue test” of the PavementExamination Method Manual were performed, and comparison of cracksuppression effectiveness was carried out. Test piece for bending testwas prepared according to “bending test” of Pavement Examination MethodManual, and attachment of the road reinforcement sheet and similar sheetwas carried out by lamination to a lower side of the asphalt mixture oftest object by heat of asphalt mixture to be united. Test was carriedout according to Pavement Examination Method Manual, and bendingstrength, strain at fracture, displacement to fracture, and fractureenergy were measured.

A test piece of repeated bending fatigue test was prepared according to“bending test” of Pavement Examination Method Manual. Size of the testpiece was 50 mm×50 mm×400 mm. In the test method, a constant temperaturebath of a testing machine was maintained at 5° C. and 20° C., and loadcontrol was given in trisection loading at 5 Hz of loading rate, and anumber of times of loading until a predetermined deformation (2 mm, 3mm, 5 mm) was shown was investigated. Load given was set to 50% and 75%of a bending breaking strength of asphalt paving mixture at 20° C.

According to test results of the bending test, a fracture energy whenusing a road reinforcement sheet showed a value of not less than 15times as high as a case where the sheet was not used, and a value of notless than 11 times as high as a case where a conventional sheet materialwas used. (Table 3)

According to results of this repeated bending fatigue test, a number oftimes of a load to a predetermined deformation when a road reinforcementsheet was used showed a value of not less than 5.5 times as high as acase where sheet was not used, and a value of not less than 7.5 times ashigh as a case where a conventional sheet material was used. (Table 4)

TABLE 3 Performance comparison for crack suppression effectiveness of aroad reinforcement sheet by bending test Bending Displacement Fracturestrength Strain at to fracture energy Test object N/cm² fracture mmkN-mm Road reinforcement 912.4 5.6 × 10⁻³ 3.9 13.6  sheet With no sheet869.3 4.0 × 10⁻³ 1.2 0.9 Similar sheet 1 for 903.6 5.2 × 10⁻³ 1.4 1.2comparison (thickness 2 mm) Similar sheet 2 for 758.5 5.2 × 10⁻³ 1.2 0.8comparison (thickness 3 mm)

TABLE 4 Performance comparison for crack suppression effectiveness of aroad reinforcement sheet by repeated bending fatigue test Testtemperature 5° C. Test temperature 20° C. Load 705.6N Load 1048.6N Load705.6N Load 1048.6N Displace- Displace- Displace- Displace- ment 2 mmment 3 mm ment 5 mm ment 5 mm Number of Number of Number of Number ofTest times of times of times of times of object loading loading loadingloading Road 31,667 25,000 7,333 700 reinforce- ment sheet With no 5,6674,667 833 300 sheet Similar 2,333 2,333 567 300 sheet 1 for compari- son(thickness 2 mm) Similar 4,000 3,000 633 300 sheet 2 for compari- son(thickness 3 mm)

Experiment 4 execution test for crack suppression effectiveness, andcrack suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

Three sections (width of 4 m×length of 10 m) were dug down about 80 cm,and 40 cm lower layer subbase course (7) was prepared by crusher in thesubgrade. Furthermore, an upper subbase course (8) with 25 cm wasprepared with mechanically stabilized crushed stone on it.

A styrene foam plate (9) with a thickness of 5 cm was laid in order toform an condition where a subbase course (6) was softened on the uppersubbase course (8). Furthermore, 8 cm of a layer of asphaltstabilization (10) was paved to prepare a test section.

Each of this test section was classified into a first section in which aroad reinforcement sheet was not paved and a binder course (5) and asurface course (4) were paved, a second section in which a roadreinforcement sheet was paved under the binder course (5), and a thirdsection in which a road reinforcement sheet was paved under the surfacecourse (4), and pavement test was carried out.

In the first section, on a layer of asphalt stabilization (10) 5 cm ofbinder course (5) and 5 cm of surface course (4) were paved without aroad reinforcement sheet to prepare a paved road. In the second section,a road reinforcement sheet was paved on a layer of asphalt stabilization(10), subsequently 5 cm of binder course (5) and 5 cm of surface course(4) were paved to prepare a paved road. In the third section, 5 cm of abinder course (5) was paved on a layer of asphalt stabilization (10),subsequently on it a road reinforcement sheet was paved, and 5 cm of asurface course (4) was paved to prepare a paved road.

In all of the above described asphalt pavings, manufacturing deliveringwas carried out at 140° C., and the delivered material was used. Placingand spreading by usual asphalt finisher having a single tamper and avibration screen were carried out. Rolling compaction was carried out bya large-sized vibration roller and a pneumatic tire roller at rollingtemperature of 110° C. In the test, at 12 hours after the finalizationof pavement, road was opened and observation of pavement face wascarried out.

After the road was opened, there was a vehicular traffic of an averageof 6000 per day.

Surface course crack forming period of the pavement face showed 1.6thyear for the first section, 2.9th year for the second section, and 3.6thyear for the third section respectively.

Next, a thickness of a surface course asphalt of the second section andthe third section were set to 4 cm to carry out a test, and a markedlymore excellent result than in the first section as in the case of 5 cmwas obtained.

Experiment 5 execution test for crack suppression effectiveness, andcrack suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

In a road whose traffic volume is D-case, after established road surfacewas cut by 10 cm, a road reinforcement sheet was paved on an existing RCfloor slab (11) joint, and subsequently two-layer overlay by a 4 cm ofbinder course (5) (improved type II dense-graded asphalt mixture) and bya 4 cm of surface course (4) (asphalt mixture for drainage pavement) wascarried out.

Pavement method of construction was according to asphalt pavingrequirements, and was the same as conventional paving method. In pavingof a road reinforcement sheet, the road reinforcement sheet concernedwas paved while pouring heated and molten asphalt. Road surfacesituation at one year and a half after execution was observed. Then, itwas confirmed that crack was not contained after one year and a half inthe surface course asphalt.

Experiment 6 execution test for crack suppression effectiveness, andcrack suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

In a road whose traffic volume is D case, after established road surfacewas cut by 4 cm, a road reinforcement sheet was paved in a part of crackthrough surface course to lower layer mastic asphalt layer (12), and 4cm of one-layer overlay by a surface course (4) (dense-graded asphaltmixture) was carried out.

Pavement method of construction was according to asphalt pavingrequirements, and was the same as conventional paving method. In pavingof a road reinforcement sheet, the road reinforcement sheet concernedwas paved while pouring heated and molten asphalt. Road surfacesituation at one year and a half after execution was observed. Then, itwas confirmed that crack was not contained after one year and a half inthe surface course asphalt.

Experiment 7 performance comparison for rutting suppressioneffectiveness

In a case where a road reinforcement sheet obtained in experiment 1 wasused, where a sheet was not used, and where a similar sheet was used,“wheel tracking test” of Pavement Examination Method Manual was carriedout, and a comparison of rutting suppression effectiveness was carriedout.

Test piece was prepared according to 3-3-7 “wheel tracking test” ofPavement Examination Method Manual, and attachment of a roadreinforcement sheet and a similar sheet was carried out according toeach sheet execution manual. In test method, dynamic stability wasmeasured according to Pavement Examination Method Manual. According tothis wheel tracking test results, a dynamic stability when using a roadreinforcement sheet showed a value of not less than 1.5 times as high asin a case where a sheet was not used, and of not less than 2.5 times ashigh as in a case where a conventional sheet material was used. (Table5) Moreover, it was confirmed that it had a sufficient strength when asurface course was 3 cm, and that a thin surfacing might be possible.

TABLE 5 Performance comparison for rutting suppression effectiveness ofa road reinforcement sheet Dynamic Cross section of test objectstability constitution Sheet (turn/mm)

Road reinforcement sheetWith no sheetSimilar sheet 1 for comparison (2mm thickness)Similar sheet 2 for comparison (3 mm thickness)1,004666395245

Road reinforcement sheetWith no sheetSimilar sheet 1 for comparison (2mm thickness)Similar sheet 2 for comparison (3 mm thickness)658666345209

Experiment 8 execution test for rutting suppression effectiveness, andrutting suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

In a road whose traffic volume is C-case, on a surface where 5 cm cutwas given (13), two portions were prepared where a road reinforcementsheet was paved and where not paved, and subsequently, one-layer overlay(5 cm) was carried out by surface course (4) (improved II typedense-graded asphalt mixture).

Road surface situation at one year after execution was measured withcrossing profiling meter. Pavement method of construction was accordingto asphalt paving requirements, and was the same as conventional pavingmethod. In paving of a road reinforcement sheet, the road reinforcementsheet concerned was paved while pouring heated and molten asphalt.

(Table 6)

Next, a test was carried out by setting a thickness of a cut face (13)to 4 cm, and a markedly excellent result as in a case by 5 cm wasobtained.

TABLE 6 Measured part Amount of rut 1 Amount of rut 2 With reinforcementsheet 2.88 mm 1.55 mm Without reinforcement sheet 3.41 mm 3.25 mm

In Table 6, amount of rut 1 and 2 shows data in different places on aroad.

Experiment 9 execution test for rutting suppression effectiveness, andrutting suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

In a road whose traffic volume is D case, two portions were preparedwhere a road reinforcement sheet was paved and where not paved, afterjet cement (14) was applied by a floor slab top face thickening method,and subsequently, one-layer overlay (5 cm) was carried out by a drainagepavement (15).

Road surface situation after execution and after one year was measuredwith a crossing profiling meter. Pavement method of construction wasaccording to asphalt paving requirements, and was the same asconventional paving method. In paving of a road reinforcement sheet, theroad reinforcement sheet concerned was paved while pouring heated andmolten asphalt.

(Table 7)

Next a test was carried out by setting one-layer overlay to 4 cm, amarkedly excellent result as in a case by 5 cm was obtained.

TABLE 7 Measured part Amount of rut With reinforcement sheet 3.68 mmWithout reinforcement sheet 4.81 mm

Experiment 10 execution test for crack suppression effectiveness, andcrack suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

After 3 cm of established road surface was cut, a road reinforcementsheet was paved on a part where a crack was formed in the cut roadsurface (13), and subsequently one-layer overlay of 3 cm in surfacecourse (5) (improved II type dense-graded asphalt mixture) (as theimproved II type asphalt, Senafurto, trade name: product manufactured byBRIDGESTONE CORPORATION, was used) was carried out. Pavement method ofconstruction was according to asphalt paving requirements, and was thesame as conventional paving method. In paving of a road reinforcementsheet, the road reinforcement sheet concerned was paved while pouringheated and molten asphalt. Road surface situation at one year afterexecution were observed. Then, it was confirmed that crack was notcontained after one year and a half in the surface course asphalt.

Experiment 11 execution test for crack suppression effectiveness, andthe crack suppression effectiveness evaluation

[Execution Test]

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

After 3 cm of established road surface was cut, a road reinforcementsheet was paved on a part where a crack was formed in the cut roadsurface (13), and subsequently one-layer overlay of a drainage pavementroad surface (15) 3cm was carried out. Pavement method of constructionwas according to asphalt paving requirements, and was the same asconventional paving method. In paving of a road reinforcement sheet, theroad reinforcement sheet concerned was paved while pouring heated andmolten asphalt. Road surface situation at one year after execution wereobserved. Then, it was confirmed that crack was not contained after oneyear and a half in the surface course asphalt.

Experiment 12 execution test for rutting suppression effectiveness, andrutting suppression effectiveness evaluation

Pavement test was carried out using a road reinforcement sheetmanufactured in experiment 1.

A binder course (coarse-graded asphalt mixture) was paved 4 cm on a roadsurface (13) that was cut by 8 cm, two portions were prepared where aroad reinforcement sheet was paved and where not paved, andsubsequently, a surface course (improved II type dense-graded asphaltmixture) was paved by 4 cm. Pavement method of construction wasaccording to asphalt paving requirements, and was the same asconventional paving method. In paving of a road reinforcement sheet, theroad reinforcement sheet concerned was paved while pouring heated andmolten asphalt. Road surface situation at one year after execution wasmeasured with a crossing profiling meter. Measurement results are shownin Table 8.

TABLE 8 Measured part Amount of rut 1 Amount of rut 2 With reinforcementsheet 2.55 mm 1.25 mm Without reinforcement sheet 3.51 mm 3.35 mm

Experiment 13 performance comparison of crack suppression effectivenessin drainage property road

“Bending test” was carried out to compare crack suppressioneffectiveness, in a case where a road reinforcement sheet obtained byexperiment 1 was used, and where a reinforcement sheet was not used.

Test piece of the bending test had a size of 50 mm×50 mm×300 mm, andmeasurement was performed using asphalt mixture for drainage pavement.Attachment of the road reinforcement sheet was carried out by laminationto a lower side of the asphalt mixture of test object by heat of asphaltmixture to be united. Bending strength, displacement to fracture (amountof deflection), and fracture energy were measured. Results are shown inTable 9.

From results of Table 9, a fracture energy when reinforcement sheet wasused showed about 14 times as large as in a case where the sheet was notused.

TABLE 9 Performance comparison in crack suppression effectiveness ofroad reinforcement sheet Bending Amount of Fracture strength deflectionenergy (MPa) (mm) (J) With Road reinforcement sheet used 8.90 2.5 7.32Without sheet 4.56 0.5 0.51

Experiment 14 performance comparison for rutting suppressioneffectiveness in drainage property road

In two cases where a road reinforcement sheet obtained by experiment 1was used, and where a reinforcement sheet was not used, “wheel trackingtest” was carried out to compare dynamic stability.

A asphalt mixture for drainage pavement as in experiment 13 was used,laminated and measured. Results are shown in Table 10.

TABLE 10 Performance comparison for rutting suppression effectiveness indrainage property road Dynam- Type of With or ic surface withoutstability Cross section of test object course reinforce- (turn/constitution asphalt ment sheet mm)

Drain-agepropertyasphalt WithWithout 6,4433,529

According to results of Table 10, dynamic stability in a case where areinforcement sheet was used showed approximately twice as high as theone in a case where the sheet was not used.

In addition, a test was carried out for a sheet used in this Exampleaccording to shearing adhesive strength test of Japan Highway PublicCorporation Research Institute data No. 124, exfoliation betweenreinforcement sheet/asphalt layer was not observed.

Example 14 and Comparative Example

Using various reinforcements, various reinforcement sheets were arrangedon top of binder course asphalt with a thickness of 20 mm, then testpieces of surface course asphalt with a thickness of 40 mm were preparedthereon, and bending test was carried out. Results are shown in Table11. In addition, improved asphalt II type of 13 mm dense-graded was usedas asphalt.

TABLE 11 Strength of Amount of initial crack deflections to Energy toformation fracture fracture (KN) (mm) (J) Without 7.4 1.23 2.80reinforcement sheet Preglon 8.1 1.83 7.69 GF reinforced type A 6.6 1.143.09 GF reinforced type B 6.6 1.04 2.12 GF reinforced type C 6.5 1.103.03 Synthetic fiber 7.2 1.09 2.24 reinforced type

INDUSTRIAL APPLICABILITY

A road reinforcement sheet, and a structure of asphalt reinforced pavedroad of the present invention show a remarkably excellent durability torutting and crack of asphalt paving that are generated by increase intraffic, and increase in traffic load which are becoming social problemsin recent years.

With the above described performance, especially a thin surfacing (thinlayer pavement) paving with thickness of asphalt made thinner becomespossible, and, as a result, following effectiveness may be acquired;

-   1. Cost cut and shortening of time required for completion are    attained by reduction of amount of asphalt used;-   2. Since in a case of road repairing with a thin surface course, the    amount of wastes is reduced, cutting time is shortened, traffic    interrupting time of a road is shortened, and environmental    problems, such as noise, are mitigated;-   3. Since traffic of car is enabled on the reinforcement sheet itself    of the present invention, passing of car is enabled even during the    construction, and thus time necessary for completion is greatly    shortened.

1. A paved road including a reinforcement sheet layer (1A) and apavement layer (22), wherein said reinforcement sheet layer (1A)includes an asphalt layer (2) laminated to at least one side of areinforcement sheet (1) including a composite material that isimpregnated with a thermoplastic resin so that a volume content of acontinuous glass fiber is not less than 30% and not more than 85% usingthe continuous glass fiber as reinforcement fiber, and a thickness ofthe pavement layer (22) is 40 to 15 mm, wherein the paved road resistsrutting and cracking under heavy automobile traffic conditions.
 2. Thepaved road according to claim 1, wherein the reinforcement sheet layer(1A) is further a reinforcement sheet layer (1B) having a woven fabriclayer or a nonwoven fabric layer (3) containing natural fiber orsynthetic fiber on at least a part of face between the reinforcementsheet (1) and the asphalt layer (2).
 3. The paved road according toclaim 1, including a reinforcement sheet layer (1A) and a pavement layer(22), wherein said reinforcement sheet layer (1A) includes an asphaltlayer (2) laminated to both sides of a reinforcement sheet (1) includinga composite material that is impregnated with a thermoplastic resin sothat a volume content of a continuous glass fiber concerned is not lessthan 30% and not more than 85% using the continuous glass fiber asreinforcement fiber.
 4. The paved road according to claim 1, wherein thereinforcement sheet (1) has a tensile strength of not less than 290MPas, a tensile elongation of not more than 10%, a coefficient ofthermal expansion of 2×10⁻⁶ to 8×10⁻⁶/° C., and a thickness of 100micrometers to 600 micrometers.
 5. The paved road according to any ofclaims 1 to 3, wherein the asphalt layer (2) has a thickness of not lessthan 400 micrometers and not more than 2000 micrometers.
 6. The pavedroad according to claim 1, wherein, when shearing peel strength beingperformed for the reinforcement sheet (1) and the asphalt layer (2), thelayers are bonded mutually with a strength of not less than a force ofcoagulation of asphalt layer (2).
 7. The paved road according to claim 1wherein the pavement layer has a fracture energy by a bending test ofnot less than 4 kN-mm.
 8. The paved road according to claim 1 whereinthe pavement layer has a dynamic stability by a wheel tracking test ofnot less than 600 turn/mm.
 9. The paved road according to any of claims1 to 3, wherein the pavement layer (22) provides drainage, and thereinforcement sheet layer (1A or 1B) provides seepage control, the pavedroad draining rainwater in a direction of a road shoulder along an uppersurface of the reinforcement sheet layer (1A or 1B) without permeatingrainwater penetrated via the pavement layer (22) into a subbase course.10. A structure of a road comprising the paved road according toclaim
 1. 11. A structure of a temporary road used during road repairingcomprising the paved road according to claim
 1. 12. A repairing methodof a paved road comprising, after formation of a crack, rut, or lossportion on a pavement surface on the paved road with asphalt orconcrete, after at least a part of a surface of the paved road is cut,and after the crack or the loss portion is optionally partiallyrepaired, preparing the paved road according to any of claims 1 to 3.13. A repairing method of a paved road comprising, after a surface iscut and a crack or loss portion is partially repaired on the paved roadwith asphalt or concrete, preparing the paved road according to claim 9having a function of draining rainwater in a direction of a roadshoulder.